Measurement Technique Comparison in the Entire Fracture Surface Topography Assessment for Additively Manufactured Materials

This paper focuses on comparing the three microscopic measurement techniques, confocal, focus variation, and point for focus, for the evaluation of entire fracture surface topographies. The measurements were performed using a Sensofar S Neox 3D optical profilometer and the Mitutoyo QV Apex 302 vision measuring system. The test specimens required for measuring were printed through laser powder bed fusion (LPBF) technology using two materials: Stainless Steel 316L and Inconel 718. The printing was performed with a printing power of 200 W, scanning speed of 800 mm/s, and layer thickness of 30 µm or 50 µm. The measurement differences were analyzed on the basis of void volume <i>(Vv)</i>, fractal dimension (<i>Df)</i>, and texture isotropy parameters, as well as a general view of the surface topography. The obtained results did not show a comprehensible difference between the applied measurement techniques for particular specimens. Thus, both measurement devices and three measurement techniques can be used to precisely measure the dimensions of LPBF-processed specimens with the <i>entire fracture surface</i> method.